Isaiah 52:3

Ye have sold yourselves for nought - You became captives and prisoners without any price being paid for you. You cost nothing to those who made you prisoners. The idea is, that as they who had made them prisoners had done so without paying any price for them, it was equitable that they should be released in the same manner. When their captors had paid nothing for them, God would suffer nothing to be paid for them in turn; and they should be released, as they had been sold, without a price paid for them. Perhaps God intends here to reproach them for selling themselves in this manner without any compensation of any kind, and to show them the folly of it; but, at the same time, he intends to assure them that no price would be paid for their ransom.

Ye shall be redeemed - You shall be delivered from your long and painful captivity without any price being paid to the Babylonians. This was to be a remarkable proof of the power of God. Men do not usually give up captives and slaves, in whatever way they may have taken them, without demanding a price or ransom. But here God says that he designs to effect their deliverance without any such price being demanded or paid, and that as they had gone into captivity unpurchased, so they should return unpurchased. Accordingly he so overruled events as completely to effect this. The Babylonians, perhaps, in no way could have been induced to surrender them. God, therefore, designed to raise up Cyrus, a mild, just, and equitable prince; and to dispose him to suffer the exiles to depart, and to aid them in their return to their own land. In this way, they were rescued without money and without price, by the interposition of another.

52:3 Sold yourselves - By your sins, without any valuable consideration paid by them either to you, or to your Lord and owner.Without money - Without paying any ransom.